北小麝鼩的代谢产热和体温调节特征

为探讨食虫目小型哺乳动物的代谢产热和体温调节特征,本文采用封闭式流体压力呼吸仪测定了北小麝鼩在环境温度5 ～ 30℃下的静止代谢率(RMR),结果显示:在环境温度(Ta)为17 5 ～25℃ 的范围内,北小麝鼩的体温基本维持恒定,平均体温为36.55 ± 0.38℃ ;热中性区(TNZ) 为20 ～ 25℃ ;基础代谢率BMR 为5.46 ±0.23 (mLO₂ /g· h),其中环境温度在25℃ 时静止代谢率最低,为4.84 ± 0.39 (mLO₂ /g· h)。在5 ～ 25℃环境温度范围内,热传导值保持稳定;在此温度范围内,北小麝鼩的热传导率(C) 最低,平均为0.42 ± 0.01mLO₂ / (g·h·℃ )。总之,北小麝鼩的产热和体温调节特征为较高的BMR,中等的热传导率,较低的体温和较宽的热中性区。这些特征可能与该物种体型小、夜行性、主要以无脊椎动物为食等生活习性密切相关。     

Characterization of eight polymorphic microsatellites in the shrew Crocidura suaveolens and its application to the study of insular populations of the French Atlantic coast

We developed eight polymorphic microsatellite loci to study the natural populations of Crocidura suaveolens, the lesser white‐toothed shrew. These loci are used in the study of insular populations of the French Atlantic coast where these shrews exhibit gigantism features that suggest an insular syndrome. These populations were threatened by the invasion of the rat Rattus norvegicus and the eradication of this alien pest in some islands was followed by a demographic expansion of the shrew populations. These first genetic results suggest that the shrew populations in the three studied islands are very differentiated.     

Pliocene and Pleistocene diversification and multiple refugia in a Eurasian shrew (Crocidura suaveolens group)

We sequenced 998 base pairs (bp) of mitochondrial DNA cytochrome b and 799 bp of nuclear gene BRCA1 in the Lesser white-toothed shrew (Crocidura suaveolens group) over its geographic range from Portugal to Japan. The aims of the study were to identify the main clades within the group and respective refugia resulting from Pleistocene glaciations. Analyses revealed the Asian lesser white-toothed shrew (C. shantungensis) as the basal clade, followed by a major branch of C. suaveolens, subdivided sensu stricto into six clades, which split-up in the Upper Pliocene and Lower Pleistocene (1.9-0.9 Myr). The largest clade, occurring over a huge range from east Europe to Mongolia, shows evidence of population expansion after a bottleneck. West European clades originated from Iberian and Italo-Balkanic refugia. In the Near East, three clades evolved in an apparent hotspot of refugia (west Turkey, south-west and south-east of the Caucasus). Most clades include specimens of different morphotypes and the validity of many taxa in the C. suaveolens group has to be re-evaluated.     

Molecular evidence of Pleistocene bidirectional faunal exchange between Europe and the Near East: the case of the bicoloured shrew (Crocidura leucodon, Soricidae)

We sequenced 1077 bp of the mitochondrial cytochrome b gene and 511 bp of the nuclear Apolipoprotein B gene in bicoloured shrew (Crocidura leucodon, Soricidae) populations ranging from France to Georgia. The aims of the study were to identify the main genetic clades within this species and the influence of Pleistocene climatic variations on the respective clades. The mitochondrial analyses revealed a European clade distributed from France eastwards to north-western Turkey and a Near East clade distributed from Georgia to Romania; the two clades separated during the Middle Pleistocene. We clearly identified a population expansion after a bottleneck for the European clade based on mitochondrial and nuclear sequencing data; this expansion was not observed for the eastern clade. We hypothesize that the western population was confined to a small Italo-Balkanic refugium, whereas the eastern population subsisted in several refugia along the southern coast of the Black Sea.     

Evolution and biogeography of the endemic Roucela complex (Campanulaceae: Campanula) in the Eastern Mediterranean

At the intersection of geological activity, climatic fluctuations, and human pressure, the Mediterranean Basin – a hotspot of biodiversity – provides an ideal setting for studying endemism, evolution, and biogeography. Here, we focus on the Roucela complex (Campanula subgenus Roucela), a group of 13 bellflower species found primarily in the eastern Mediterranean Basin. Plastid and low‐copy nuclear markers were employed to reconstruct evolutionary relationships and estimate divergence times within the Roucela complex using both concatenation and species tree analyses. Niche modeling, ancestral range estimation, and diversification analyses were conducted to provide further insights into patterns of endemism and diversification through time. Diversification of the Roucela clade appears to have been primarily the result of vicariance driven by the breakup of an ancient landmass. We found geologic events such as the formation of the mid‐Aegean trench and the Messinian Salinity Crisis to be historically important in the evolutionary history of this group. Contrary to numerous past studies, the onset of the Mediterranean climate has not promoted diversification in the Roucela complex and, in fact, may be negatively affecting these species. This study highlights the diversity and complexity of historical processes driving plant evolution in the Mediterranean Basin.     

The reproductive ecology of Medicago citrina (Font Quer) Greuter (Leguminosae): a bee-pollinated plant in Mediterranean islands where bees are absent

The reproductive ecology of Medicago citrina was studied in the Columbretes archipelago (Mediterranean Sea), where bees are absent. The flowers were self-compatible, homogamous, nectar producers, depended on large floral visitors for tripping and pollination. Several characteristics of the reproductive biology of M. citrina indicate an adaptation to an isolated environment characterised by scarcity of appropriate pollinators. As a result of this scarcity, fruit and seed set under natural conditions were significantly lower compared to hand-pollination treatments. The main flower visitors were mostly flies and blowflies, with Eristalis tenax (Syrphidae) and Calliphora vicina (Calliphoridae) being the most efficient pollinators. We argue that because M. citrina faces pollen limitation in the small islets of Columbretes, it presents an interesting case study of pollination related to island endemism and diversity.     

Cryptic diversity and multiple origins of the widespread mayfly species group Baetis rhodani (Ephemeroptera: Baetidae) on northwestern Mediterranean islands

How the often highly endemic biodiversity of islands originated has been debated for decades, and it remains a fervid research ground. Here, using mitochondrial and nuclear gene sequence analyses, we investigate the diversity, phylogenetic relationships, and evolutionary history of the mayfly Baetis gr. rhodani on the three largest northwestern Mediterranean islands (Sardinia, Corsica, Elba). We identify three distinct, largely co‐distributed, and deeply differentiated lineages, with divergences tentatively dated back to the Eocene–Oligocene transition. Bayesian population structure analyses reveal a lack of gene exchange between them, even at sites where they are syntopic, indicating that these lineages belong to three putative species. Their phylogenetic relationships with continental relatives, together with the dating estimates, support a role for three processes contributing to this diversity: (1) vicariance, primed by microplate disjunction and oceanic transgression; (2) dispersal from the continent; and (3) speciation within the island group. Thus, our results do not point toward a prevailing role for any of the previously invoked processes. Rather, they suggest that a variety of processes equally contributed to shape the diverse and endemic biota of this group of islands.     

Phylogeographical footprints of the Strait of Gibraltar and Quaternary climatic fluctuations in the western Mediterranean: a case study with the greater white-toothed shrew, Crocidura russula (Mammalia: Soricidae)

We used mitochondrial cyt b sequences to investigate the phylogenetic relationships of Crocidura russula (sensu lato) populations across the Strait of Gibraltar, western Europe, Maghreb, and the Mediterranean and Atlantic islands. This revealed very low genetic divergence between European and Moroccan populations. The application of a molecular clock previously calibrated for shrews suggested that the separation of European from Moroccan lineages occurred less than 60 000 bp, which is at least 5 million years (Myr) after the reopening of the Strait of Gibraltar. This means that an overwater dispersal event was responsible for the observed phylogeographical structure. In contrast, genetic analyses revealed that Moroccan populations were highly distinct from Tunisian ones. According to the molecular clock, these populations separated about 2.2 million years ago (Ma), a time marked by sharp alternations of dry and humid climates in the Maghreb. The populations of the Mediterranean islands Ibiza, Pantelleria, and Sardinia were founded from Tunisian populations by overwater dispersal. In conclusion, overwater dispersal across the Strait of Gibraltar, probably assisted by humans, is possible for small terrestrial vertebrates. Moreover, as in Europe, Quaternary climatic fluctuations had a major effect on the phylogeographical structure of the Maghreb biota.     

Genetic diversity and evolutionary history of the Tyrrhenian treefrog Hyla sarda (Anura: Hylidae): adding pieces to the puzzle of Corsica–Sardinia biota

The Corsica–Sardinia archipelago is a hotspot of Mediterranean biodiversity. Although tempo and mode of arrival of species to this archipelago and phylogenetic relationships with continental species have been investigated in many taxa, very little is known about the current genetic structure and evolutionary history subsequent to arrival. In the present study, we investigated genetic variation within and among populations of the Tyrrhenian treefrog Hyla sarda, a species endemic to the Corsica–Sardinia microplate and the surrounding islands, by means of allozyme electrophoresis. Low genetic divergence (mean D_nei = 0.01) and no appreciable differences in the levels and distribution of genetic variability (H_E: 0.06–0.09) were observed among all but one populations (Elba). Historical demographic and isolation‐by‐distance analyses indicated that this diffused genetic homogeneity could be the result of recent demographic expansion. Along with paleoenvironmental data, such expansion could have occurred during the last glacial phase, when wide and persistent land bridges connected the main islands and a widening of lowland areas occurred. This scenario is unprecedented among Corsica–Sardinia species. Together with the lack of concordance even among the few previously studied species, this suggests either that species had largely independent responses to paleoenvironmental changes, or that most of the history of assembly of the Corsica–Sardinia biota is yet to be written. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 159–167.     

Morphotypic variability of masticatory surface pattern of molars in the recent and Pleistocene Lemmus and Myopus (Rodentia,Cricetidae) of Europe and Western Siberia

In this article, we present the results of morphological study, applying multivariate statistical analysis, of seven samples of recent Lemmini species (Lemmus lemmus, L. sibiricus, Myopus schisricolor) and eight samples of the ancient Siberian lemmings from the Middle and Late Pleistocene localities, mainly in northeastern Europe. On the basis of studying variability of masticatory surface pattern of molars, 24 morphotypes have been described. The differences in morphotypes frequencies were found between the recent Myopus and Lemmus and between the two Norwegian lemming samples. There are some indications of an evolutionary trend in molar morphology of the Siberian lemmings of the Middle, Late Pleistocene, and the recent of Eastern Europe. The distinctions, at least, between the Middle Pleistocene and modern lemmings exceed a species level.     

Evolutionary history of the greater white-toothed shrew (Crocidura russula) inferred from analysis of mtDNA, Y, and X chromosome markers

We investigate the evolutionary history of the greater white-toothed shrew across its distribution in northern Africa and mainland Europe using sex-specific (mtDNA and Y chromosome) and biparental (X chromosome) markers. All three loci confirm a large divergence between eastern (Tunisia and Sardinia) and western (Morocco and mainland Europe) lineages, and application of a molecular clock to mtDNA divergence estimates indicates a more ancient separation (2.25 M yr ago) than described by some previous studies, supporting claims for taxonomic revision. Moroccan ancestry for the mainland European population is inconclusive from phylogenetic trees, but is supported by greater nucleotide diversity and a more ancient population expansion in Morocco than in Europe. Signatures of rapid population expansion in mtDNA, combined with low X and Y chromosome diversity, suggest a single colonization of mainland Europe by a small number of Moroccan shrews >38 K yr ago. This study illustrates that multilocus genetic analyses can facilitate the interpretation of species' evolutionary history but that phylogeographic inference using X and Y chromosomes is restricted by low levels of observed polymorphism.     

Extinction of the autochthonous small mammals of Mallorca (Gymnesic Islands, Western Mediterranean) and its ecological consequences

Aim To investigate the chronology, causes and consequences of the extinction of the autochthonous Pleistocene small mammals of Mallorca. Location Mallorca (Gymnesic Islands, Balearics, Western Mediterranean). Methods We have obtained the first direct ¹⁴C ages from the bone collagen of selected samples of two extinct endemic small mammals from Mallorca: the Balearic dormouse, Eliomys morpheus (Rodentia: Myoxidae) and the Balearic shrew, Asoriculus hidalgoi (Soricomorpha: Soricidae). We also present evidence for the absence of both endemics from the earliest Mallorcan archaeological sites and for the introduction of the garden dormouse, Eliomys quercinus, and the wood mouse, Apodemus sylvaticus. Combined information from direct dating of bone collagen of E. quercinus and A. sylvaticus and from cultural associations provides an adequate framework to establish the chronology of the faunal change and to compare it with the chronological information available on climatic change and the first arrival of humans on the islands. Results The chronological record includes the latest evidence available for the survival of endemic species and the earliest introduction of small mammals into Mallorca. We present ‘uncertainty periods for extinction’ (UPEs) of both endemic mammals based on the chronology of their last occurrence and on the inferred timing of their extinction (restricted UPEs). Main conclusions Possible causes for the extinction of autochthonous small mammals on Mallorca are discussed. Once we have discarded climatic causes, predation by invasive species, competition with newcomers and habitat deterioration, the introduction of diseases emerges as the most reasonable explanation for these extinctions. Based on the identification of changes in keystone species in Mallorcan ecosystems, we propose a tentative schedule of key ecological changes that have taken place over the past 5 millennia.     

Microsatellite markers for the Ussuri white-toothed shrew (Soricidae: <Emphasis Type="Italic">Crocidura lasiura</Emphasis>) developed by Ion Torrent sequencing and their application to the shrew populations in disturbed forests

Understanding the impacts of forest management practices on genetic diversity is essential for effective animal management and conservation. We characterized novel microsatellite loci in the Ussuri white-toothed shrew (Crocidura lasiura Dobson, 1890) to test the impacts of anthropogenic thinning of forest trees on the shrew populations and their genetic diversity. Using Ion Torrent sequencing technology, we characterized 611 potential microsatellite markers with complete di- to tetra-nucleotide motifs, identifying nine polymorphic loci. The observed and expected heterozygosities across the nine loci were 0.526 and 0.527, respectively. Mean allelic diversity was 5.2 alleles per locus, with the mean polymorphism information content at 0.498. In comparison among shrew populations, which inhabited in the forests thinned in 2004 (CLA; n = 10), 2008 (CLB; n = 9) and 2014 (CLC; n = 3), the observed heterozygosities are similar among the three populations (0.525 at CLA, 0.532 at CLB and 0.519 at CLC), whereas the expected heterozygosities were much lower in population of CLC (0.377) than that of CLA (0.509) and CLB (0.533). The small sample size at CLC limited effective comparison and evaluation of the impact of forest thinning on genetic diversity in this shrew population. Future application of the species-specific microsatellite markers described here to a larger sample size would be valuable in estimating the ecological parameters of shrew populations associated with existing forest management practices.     

Identifying zones of phenetic compression in West Mediterranean butterflies (Satyrinae): refugia,invasion and hybridization

Aim Distinct insular populations are generally considered important units for conservation. In island–mainland situations, unidirectional introgressive gene flow from the most abundant, typically continental, populations into the smaller island populations can erase native insular genetic units. As an indication of threat, the concept of phenetic slope is developed, a measure proportional to differentiation and to geographical proximity. Location The Western Mediterranean, including the following islands: Sardinia, Sicily, Corsica, Balearics, circum‐Italian, circum‐Sicilian and circum‐Sardo‐Corsican archipelagos. Eastern Europe is included for comparison. Methods Geometric morphometrics was applied to 2392 male genitalia of seven butterfly species groups. Geographic Information System techniques were used to depict the pattern in the distribution of morphotypes. The slope of variation in genital shape was computed to highlight geographical areas showing abrupt morphological changes. Correlation analyses were performed between the mean slope values across sea straits separating islands and nearest sources and ecological traits of the species that underlie their colonization and migration capacity. Results Phenetic slope analysis has revealed that the strait of Messina and the northern Tyrrhenian Sea support particularly contrasting populations. In these areas, mean slopes for species also correlated with certain ecological traits of the species. Sardinia emerges as the most stable refugium for ancestral mediterranean populations. Main conclusions There is strong support for the hypothesis that Italy has experienced invasion by populations from Eastern Europe with postglacial expansion of these populations across Italy. However, propagules are impeded from invading islands by the expanse of sea straits. Even so, sea straits are not invariably barriers. Our results suggest that wind direction in combination with habitat occupancy may have maintained ancestral insular populations in key locations distinguished by phenetic compression. We conclude that native insular populations acting as barriers to introgression in the areas showing particularly steep phenetic slopes deserve attention in conservation programmes.     

Ogasawaracris gloriosus, a new genus and species of possibly extinct grasshopper (Orthoptera: Acrididae) from the Ogasawara Islands

A new grasshopper genus and species of the subfamily Eyprepocnemidinae, Ogasawaracris gloriosus, is described from the Ogasawara Islands, oceanic islands south of Japan. This species has unique characteristics, such as an extraordinarily large body, rugose and very coarse punctation on the lateral surface of the pronotum, and very strong pronotal lateral carinae. Specimens of this new species have rarely been collected and they are known only from the Ogasawara Islands. The species may already be extinct.     

DNA taxonomy, phylogeny and Pleistocene diversification of the Cicindela hybrida species group (Coleoptera: Cicindelidae)

Species delimitation is complicated where morphological variation is continuous or poorly subdivided, but for taxonomic convenience it is common practice to separate and name geographical groups to capture this variation. DNA-based approaches may be used to test if these groups in fact represent historically divided, discrete species entities. The Cicindela hybrida complex (Coleoptera: Cicindelidae) is an assemblage of up to seven morphologically recognized species and 15 subspecies with wide distribution in the Palaearctic region. We sequenced a discontinuous segment of 1899 bp of mtDNA including three regions (coxI, rrnL+trnL2+nad1, cob) for a total of 99 specimens from 36 sampling localities across Europe, revealing 48 haplotypes. Four major clades could be identified corresponding to geographical groups from central Iberia, Ukraine, central Europe, and a band from the Atlantic Iberian coast to northern Europe. Taking into account further subdivisions within these clades, four of the six named species included in the analysis were recognizable by applying various procedures for species delimitation. Age estimates from calibrated molecular clocks date the diversification of the hybrida group within the past 2 million years (Myr), and the separation of the northern clade within 0.4 Myr. Nested clade analysis revealed the rapid range expansion of the northern group consistent with postglacial dispersal, but we did not find support for specific source population(s) in the postulated southern refugia. The evolutionary framework based on mtDNA sequences is shown to identify species entities as discrete clusters of closely related sequences and provides an objective system for delineating and recognizing hierarchically structured groups. In the case of the C. hybrida complex, these groups largely coincided with those established from morphology. The study adds further support to the utility of mtDNA-based sequence profiles (the 'DNA taxonomy') as a rapid and objective synthesis of evolutionary diversity and as reference system for communication.     

Genetic differentiation of Diplodus sargus (Pisces: Sparidae) populations in the south-west Mediterranean

Allozyme analysis of tissue samples of 1249 white sea bream Diplodus sargus from five localities of the south-west Mediterranean revealed a high degree of genetic polymorphism. The observed heterozygosity ranged from 0.4182 (Cape of Palos) to 0.3138 (Tabarca). Several populations were characterized by unique alleles. Examination of the spatial structure was performed using Nei's distances and F- statistics, and indicated genetic differences between groups. One group, which clustered Tabarca and Guardamar, could be explained by the small geographical distance between them. Mazarrón and Cape of Palos samples showed genetic divergence from other samples (Guardamar, Tabarca and Águilas) and this difference may be as a result of local current systems and larval dispersal.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 82 , 249–261.     

Geographic isolation and evolution of Mediterranean endemic Cyclamen: insights from chloroplast trnL (UAA) intron sequence variation

 In this study we construct a phylogenetic hypothesis for the relatedness among disjunct subspecies of Cyclamen repandum and its two allopatric congeners, C. creticum and C. balearicum in order to examine the evolutionary divergence of currently isolated populations across the western Mediterranean. The most parsimonious phylogenetic tree obtained from sequencing the cpDNA trnL (UAA) intron suggests a major phylogeographic divide in southern Greece between two clades. The first clade comprises samples of C. repandum subsp. peloponnesiacum (from the Peloponnese) and C. creticum (from Crete). The second comprises samples of C. repandum subsp. repandum (from Croatia, Italy, southern France, Corsica, Sardinia and Sicily), C. repandum subsp. rhodense (from Rhodes and Kos) and C. balearicum (from the Balearic Islands and southern France). These data suggest that C. creticum has evolved in allopatry from C. repandum subsp. peloponnesiacum and that C. balearicum and C. repandum ssp. rhodense have diverged from C. repandum subsp. repandum at its western and eastern distribution limits. At one small site on Corsica, a population of C. repandum may have introgressed with relictual populations of C. balearicum. These divergence patterns illustrate how a phylogenetic perspective can be used to better understand the evolution of endemism in the Mediterranean flora. Received February 19, 2001 Accepted August 22, 2001